Guide for rock drills



April 22, F1930.' R GRIP-HTH 1,755,255

GUIDE FOR ROCK DRILLS Filed Nov. 5, 1926 Patentedy Apr. 22,v 1930 UNITED STATES RICHARD GRIFFITH, oF IIYDEVILIE, VERMONT, ASsIGNoR, BY MESNE ASSIGNMENTS,

PATENT OFFICE TO TI-IErvGARDNER-DENVER, COMPANY, OF QUINCY, ILLINOIS, A CORPORATION F DELAWARE GUIDE FoRRooK ,DRILIJs` Application filed November 5, 1926. Serial No. 146,519.

The present invention relates to means for positioning a drill steel, and the object isto provide a novel structure, by means of which a series of holes can be drilled at absolutely equi-distant points, and with great accuracy, thus obvia-ting serious diiiiculty heretofore experienced in connection with the drilling of holes where they are apt to run olf at'vaf rious angles, and thus leave dierent th1ck- .10 nessesof material betweenr them.

In the accompanying drawings :Y

Figure 1 is a side yelevation of one embodiment of the invention,

Figure 2 isa plan view of the same, y

Figure 3 is a vertical sectional vview on the line 3-3 of Figure 1,

Figure 4 is an end elevation,

Figure 5 is a plan view' of the bushing employed. j

In the embodiment disclosed, an elongated body, preferably ofone piece, is provided. In the present structure, this body is shown as comprising an upper horizontal bar 4 and alower horizontal bar. 5 connected by integral end portions 6, though other forms may be employed. Through the bars 4 and 5 are formed vertical guide openings 7, these openings'rbeing of sulicient diameter to permit the passage therethrough .of the bit of a drill steel, 'and consequently being of greater d1- ameter than the shank of such steel. The end portions are provided with vertical bores 8 and 9.

In the bore 8 is located a vertically ldisposed anchor stem 10 that is slidab-le in said bore and extends a considerable distance below'the body. This vstem is of a size to engage in a hole drilled in the rock. The stem is provided with a longitudinal groove 11 that is preferably tapered downwardly, and in said groove is slidably fitted a clamping wedge 12 that projects above the upper end of the, stem* and extends below the body. Thiswedge has its upper endportion projectingoutwardly beyond the stem, and titting in a groove 13 formed at. oney side of the opening 8. The projecting portion is provided with a series of teeth` 14. Theend of the body outside the groove 13 is enlarged .5.0 at' 15, and is formed with a-fnotch o r seat 16.

The bottom of this seat 17 constitutes the fulcrum for a tool lever 18. The inner end of said lever is tapered to form a tooth 19 adapta cross pin 20, the length ofwhich is greater than the diameter of the drilled hole, and this cross pin is also adapted to seat in notches 21 formed in the bottom of the body alongside theopening 8, and said pin prevents detachment of the stem from the body 4.

In the other end bore 9 is fitted a'holding stem 22 that projects above and below ythe body, the upper end constituting a-hammering head, the lower endk being sharpened to form a bit 23. Set screws 24 serve to clamp the two stems against movement. y

A bushing is provided to detachably lit in the guide openings 7. This bushing prefer ably consists of longitudinal sections 25 having ianges 26 formed on their upper ends and adapted to rest on the top of the body. The bore of the bushing is such that it will snugly but slidably receive the drill steel. A portion of such steel is shown at 27, the bit thereof being indicated at'28.

This structure is usedsubstantially as -follows. When a' hole has beenV drilled, the lower end of the stem 10'is engaged therein, the cross pin 20"limiting the downward'movementof said stem into the'hole.v The body is then moved until the series of guide openings 7 are directly over and in line with the points for the Series of holes to be drilled.

vThe wedge12 is then driven-downwardly and serves to`securely fix thestem in the drilled hole, as well as fasten the body to the stem. The supporting pin is then driven into the stone avshort distance as indicated in Figure 1 and is clamped by the set screws. The bit of the drill steel is then passedthrough the lirst opening and the shank is afterwards surrounded'by the b-ushing fitted into said opening. rlhe steel is thus accurately positioned and-the first hole is drilled. After the completion of the hole, the steel is moved to theV next hole and so on until the series is coinpleted. The implement is thenl moved to the position to'drill the nextsetof holes, the

anchor stem being now engaged in the hole last drilled.

It has been found under actual practice that this device will guide the drill steel with the greatest accuracy, thus insuring that'the holes are drilled a predetermined distance apart and are equi-distant throughout their extent.

From the foregoing, it is thought that the construction, operation vand many advantages of the herein described'invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion and minor details'of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention. Y

What I claim, is:

l. In a rock drill guide, the combination with a body having a guideway for the drill steel, of` an anchor movably mounted on the body and adapted to engage in a drilled hole, and vmeans for limiting the amount of insertion of the anchor into the hole, said means also engaging the body and limiting the movement of the anchor in one direction therein.

2. In a rock drill guide, the combination with a bodyhaving guideways for the drill steel and also having a bore at one side of the guideways, of an anchor stem slidably mounted in the bore, and means for securing the stem against its sliding movement, said stem having a cross pin beneath the body.

3. In a rock drill guide, the combination with a body having guideWa-ys for the drill steel, and a bore, of an anchor stem slidable in the bore, and a clamping wedge engaging the stem and the body for holding the stem in adjusted position.

1l. In a rock drill guide, the combination with a body having guideways for the drill steel and a bore, of an anchor stem slidable in the bore, and a clamping wedge engaging the stem and the body for holding the stem in adjusted position, said wedge having a releasing tooth, and said body having a fulcrum for a releasing tool engaged with the tooth.

5. In a rock drill guide, the combination with a body having guideways for the drill steel and a bore at one end, of an anchor stem slidable in the bore and having a stop below the body, said anchor also having a longitudinal groove, and a wedge slidable in the groove and having teeth, said body having a socket .opening into the bore and providedv with a fulcruin bearing for a tool engaged with said teeth.

46. In a rock drill guide, the combination with a body having guide openings of suficientdiameter to allow the passage ofthe enlarged bit of a drill steel, of means for anchorng the body against movement, and a bushing that detachably iits in the guide openings and having a bore that snugly and slidably receives the shanlrof the drill steel above the bit and permits the free movement of the steel longitudinally and rotatably with relation to the body.

7. In a rock drill guide, the combination 'with a -body having guide openings of sufiicient diameter to permit the passage of the enlarged bit of a drill steel, of Ymeans for anchoring the body, and a bushingthat detachably fits in the guide openings and having a bore that snugly and slidably receives the shank of the drill steel above the bit, said bushing comprising longitudinally extending sections having outstanding holding flanges on their upper ends. Y Y

8. In a rock drill guide, the combination with a body provided with a series of vertical guide openings and bores in the ends ofthe body, an Vanchor stem slidably mounted in one bore, means `for clamping the stem, `a holding pin mounted in the other bore, means for securing said pin, said guide openings being of a diameter to permit the` lpassage of the enlarged bit of a drill steel, and a split bushing that detachably lits in the openings and has aV bore to snugly and slidably receive the shank of a drill steel above the bit, and permits the free movement of the steel longitudinally and rotatably with relation to the body. A

9. In a rock drill, the combination with a body having a guide for a drill steel, of an anchor movably mounted in the body for engagement in a previously drilled hole, and means for wedging the anchor in the hole, said wedging means also engaging the body and constituting a key for holding the body against rotation on the anchor.

l0. In a rock drill, the combination with a body having a guide for a drill steel, of an anchor movably mounted in the body for engagement in a previously drilled hole and having a keyway, the body also having a keyway alined with the keyway of the anchor, and a wedge slidably mounted in the keyways to hold the body against rotation on the anchor, said wedge engaging the anchor toY wedge it in its hole.

11. In a rock drill, the combination with a body having a plurality of guideways for directing a `drill steel in the drilling of Va line of holes, of an anchor stem mounted in one end of the body for engagement in a previously drilled hole, a spur shorter than the anchor stem and movably mounted in the other end Vof the body, said spur having exposed means by which it may be driven into the rock .at the end of the line of holes Vdetermined by the guideways, and means for detachably fiX- ing the spur against movement in the body after it has been so driven.

In testimony whereof, I affix my signature.

' RICHARD GRIFFITH. 

